Dimethylformamide → 4-Allyldimethylsilylbenzaldehyde
Reaction equation
[CH2:1]([C:4]1[CH:9]=[CH:8][C:7](Br)=[CH:6][C:5]=1[SiH:11]([CH3:13])[CH3:12])C=C.[C:14]([Li])([CH3:17])(C)[CH3:15].CN(C=[O:23])C.[NH4+].[Cl-]>C1COCC1>[CH2:15]([C:7]1[CH:8]=[CH:9][C:4]([CH:1]=[O:23])=[C:5]([SiH:11]([CH3:12])[CH3:13])[CH:6]=1)[CH:14]=[CH2:17]Participants
Conditions
- Temperature
- -78 °C
Procedure
To a solution of 1-allyldimethylsilyl-4-bromobenzene (1 Scheme 1, 1.3 g, 5 mmol) in dry THF (70 mL) at −78° C. was added t-butyllithium (3.0 mL, 1.7 M solution in pentane, 5.1 mmol) over a period of 10 min. After 30 min stirring at −78° C., anhydrous DMF (750 μL, 10 mmol) was added dropwise. The reaction mixture was stirred further for 1 h and warmed to room temperature. Concentrated NH4Cl (2 mL) was added to the solution, and the reaction mixture was concentrated. The residue was extracted with ethyl acetate (20 mL) and brine (5 mL), and the organic layer was dried (Na2SO4), concentrated. The crude product was purified by column chromatography (1:15 ethyl acetate/hexanes) to afford a colorless oil (860 mg, 82%); 1H NMR (300 MHz, CDCl3) δ 0.32 (s, 6 H), 1.78 (d, J=8.10 Hz, 2 H), 4.84 (s, 1 H), 4.89 (m, 1 H), 5.76 (m, 1 H), 7.67 (d, J=8.10 Hz, 2 H), 7.85 (d, J=8.10 Hz, 2 H), 10.05 (s, 1 H); 13C NMR (75 MHz, CDCl3) −3.4 (2C), 23.5, 114.2, 128.8 (2C) 133.7, 134.4, (2C), 136.9, 147.6, 192.8; HRMS calcd for C12H16OSi 204.0971, found 204.0972
Workup
- stirringThe reaction mixture was stirred further for 1 h
- temperaturewarmed to room temperature
- concentrationthe reaction mixture was concentrated
- extractionThe residue was extracted with ethyl acetate (20 mL) and brine (5 mL)
- dry with materialthe organic layer was dried (Na2SO4)
- concentrationconcentrated
- customThe crude product was purified by column chromatography (1:15 ethyl acetate/hexanes)
Sources & evidence
- ORD record
- ord-dc7d129e03d64bfebbe4ddf24cdc41d1
- Source dataset
- uspto-grants-2002_07
- Patent number
- US06416861B1
Reaction notes
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